Why do I keep shorting out the starter solenoid?

Put brand new starter in my car, worked great for about two days then it wouldn't start, so I replaced the battery cables thinking that was the problem nope, not it, at first I didn't think about the starter cause it brand new, so I tried to jump it maybe it's the battery nope come to find out it's the solenoid so replaced it again brand new starter and solenoid and again worked for two days then just quit someone mentioned to me that I may have a low or high voltage short somewhere any ideas where this could be?